JP6667024B2 - catheter - Google Patents

Description

  The present invention relates to a medical catheter inserted into a blood vessel or the like.

  Conventionally, there is provided a reinforcing portion formed of a net-like braid, and a connecting portion for connecting two adjacent reinforcing portions to each other, wherein the connecting portion serves as a node to easily bend and easily bend. A constituent catheter has already been proposed (for example, see Patent Document 1).

  In addition, a medical catheter tube having a braided structure made of a metal wire, a configuration in which the metal wire as a reinforcing material layer is reduced in diameter from a base end to a tip to ensure flexibility. It has already been proposed (for example, see Patent Document 2).

JP 2011-72562 A JP 2007-319594 A

  However, in the configuration of Patent Literature 1, since the adjacent reinforcing members are connected and connected by the linear body of the connecting portion, the joints between the reinforcing members and the connecting portion are sharp. There is a problem that a change in stiffness occurs, stress is concentrated there, and the catheter is easily broken or kinked.

  Further, in the configuration of Patent Document 2, since the metal wire as the reinforcing material layer is reduced in diameter at a constant rate from the base end to the distal end, when inserted into a blood vessel or the like, There is a problem that an arbitrary portion cannot be easily bent.

  Therefore, an object of the present invention is to provide a catheter that can easily bend a catheter at an intermediate portion and that can prevent breakage and kink of the catheter from occurring.

  <1> The invention according to claim 1 of the present application is directed to an inner layer made of a resin, a reinforcing body provided on the outer periphery of the inner layer and made of a linear body, and an outer layer made of a resin provided on the outer circumference of the reinforcing body. In the catheter having the reinforcing member, the reinforcing member is located at a position away from the distal end of the reinforcing member toward the proximal end side of the reinforcing member, and from the proximal end to the distal end side of the reinforcing member. It is characterized by having a small cross-sectional area portion in which the cross-sectional area of the linear body decreases along the longitudinal direction of the reinforcing body at a position apart from the reinforcing body.

  <2> The invention according to claim 2 of the present application is the catheter according to claim 1, wherein the cross-sectional area in the small cross-sectional area gradually decreases toward the center of the small cross-sectional area. It is characterized by.

  <3> The invention according to claim 3 of the present application is the catheter according to claim 1 or 2, wherein the outer layer includes a first resin layer that covers the small cross-sectional area, and a base formed by the small cross-sectional area. A second resin layer that covers the reinforcing body on the proximal side from the end, and a third resin layer that covers the reinforcing body on the distal side from the distal end of the small cross-sectional area portion; The catheter forming the resin layer is more flexible than the resin forming the second resin layer.

  <4> The invention according to claim 4 of the present application is the catheter according to claim 3, wherein the resin forming the first resin layer is more flexible than the resin forming the third resin layer. It is characterized by.

  <1> The catheter according to claim 1, wherein an inner layer made of a resin, a reinforcing body provided on the outer periphery of the inner layer and made of a linear body, and an outer layer made of a resin provided on the outer circumference of the reinforcing body. In the catheter having the reinforcing member, the reinforcing member is located at a position away from the distal end of the reinforcing member toward the proximal end side of the reinforcing member, and from the proximal end to the distal end side of the reinforcing member. At a separated position, since the cross-sectional area of the linear body is reduced along the longitudinal direction of the reinforcing body, the catheter has a small cross-sectional area that is an intermediate portion of the catheter. A catheter that can be easily curved, and that does not cause a significant difference in rigidity in the small cross-sectional area, so that stress in the small cross-sectional area hardly concentrates, and the occurrence of breakage and kink of the catheter can be suppressed. To provide Can.

  <2> In the catheter according to the second aspect, in the catheter according to the first aspect, the cross-sectional area in the small cross-sectional area gradually decreases toward the center of the small cross-sectional area. In the central portion of the small cross-sectional area, a portion that can be bent more easily can be formed, and the difference in rigidity becomes gentler, and the concentration of stress in the small cross-sectional area can be dispersed. Therefore, breakage and kink of the catheter can be further suppressed.

  <3> The catheter according to claim 3, wherein in the catheter according to claim 1 or 2, the outer layer is formed of a first resin layer that covers the small cross-sectional area, and a base of the small cross-sectional area. A second resin layer that covers the reinforcing body on the proximal side from the end, and a third resin layer that covers the reinforcing body on the distal side from the distal end of the small cross-sectional area portion; Since the resin forming the resin layer is more flexible than the resin forming the second resin layer, the catheter can be more easily bent at the small cross-sectional area.

  <4> In the catheter according to the fourth aspect, in the catheter according to the third aspect, the resin forming the first resin layer is more flexible than the resin forming the third resin layer. In addition, the catheter can be more easily bent at the small cross-sectional area.

FIG. 2 is a plan view showing the catheter according to the first embodiment. FIG. 2 is a partially enlarged cross-sectional view illustrating the catheter according to the first embodiment. FIG. 7 is a partially enlarged cross-sectional view illustrating a catheter according to a second embodiment. FIG. 13 is a partially enlarged cross-sectional view illustrating a catheter according to a third embodiment. FIG. 13 is a partially enlarged cross-sectional view illustrating a catheter according to a fourth embodiment. FIG. 13 is a partially enlarged cross-sectional view illustrating a catheter according to a fifth embodiment. FIG. 13 is a partially enlarged cross-sectional view illustrating a catheter according to a sixth embodiment. FIG. 13 is a partially enlarged cross-sectional view illustrating a catheter according to a seventh embodiment. It is a partial expanded sectional view showing the catheter concerning Example 8.

  Hereinafter, embodiments embodying the catheter of the present invention will be described in detail. However, the present invention is not limited to the embodiments described below, and design changes can be made as appropriate. 1 to 9, the left side is the distal side (distal side) to be inserted into the body, and the right side is the rear side (proximal side, proximal side) operated by a technician such as a doctor. is there.

[Example 1]
For example, the catheter 11 inserted into a blood vessel includes a tubular hollow shaft 21 and a connector 30 joined to the proximal end of the hollow shaft 21 as shown in FIG. In FIG. 1, the shape of the hollow shaft 21 of the catheter 11 is a linear shape. However, the hollow shaft 21 may have a curved shape on the distal end side, and is not limited to the linear shape. Further, a flexible hollow tip portion having no reinforcing member described later may be provided on the distal end side of the hollow shaft 21.

  As shown in FIG. 2, the hollow shaft 21 includes a hollow inner layer 40 made of resin, a reinforcing body 50A provided on the outer periphery of the inner layer 40, and the reinforcing body 50A so as to cover the reinforcing body 50A. And an outer layer 60 made of a resin provided on the outer periphery of the outer layer.

  Since the medical device such as a guide wire is inserted into the inner peripheral surface of the inner layer 40, the inner layer 40 is preferably formed of a resin material having excellent slipperiness. For example, as such a resin material, a fluorine-based material such as PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene-perfluoroalkylvinylether copolymer) or FEP (tetrafluoroethylene-hexafluoropropylene copolymer) There are resin and polyethylene.

  The outer layer 60 is not particularly limited, but is preferably formed of an elastomer-based resin material. For example, the outer layer 60 can be formed of a polyamide elastomer, a polyurethane elastomer, a polyester elastomer, or the like.

  The reinforcing body 50A is formed of a linear body 51A having a circular cross section wound around the outer periphery of the inner layer 40. The linear body 51A is desirably a metal wire in order to improve the rigidity of the hollow shaft 21.

  Further, as shown in FIG. 2, the reinforcing body 50 </ b> A is located at a position separated from the distal end of the reinforcing body 50 </ b> A toward the base end side, and is directed from the base end of the reinforcing body 50 </ b> A to the distal end side. A small cross-sectional area portion 71 is formed at a position spaced apart.

  The small cross-sectional area 71 will be described in more detail. As shown in FIG. 2, the linear body 51A of the small cross-sectional area 71 formed in the middle of the reinforcing body 50A (that is, the middle of the catheter 11). A taper portion 53 is formed at the boundary between the linear body 51A and the portion other than the small cross-sectional area 71, and the small cross section is smaller than the cross-sectional area of the linear body 51A other than the small cross-sectional area 71. The cross-sectional area of the linear body 51A of the area 71 decreases along the longitudinal direction of the reinforcing body 50A.

  Note that a configuration may be adopted in which a plurality of tapered portions 53 are provided in the small cross-sectional area 71, and the cross-sectional area of the linear body 51A of the small cross-sectional area 71 is reduced stepwise. In addition, the shape of the small cross-sectional area portion 71 for reducing the cross-sectional area of the linear body 51A is preferably a tapered shape in order to prevent concentration of stress, but a stepped shape can also be adopted.

  With this configuration, the catheter 11 can be easily curved at the small cross-sectional area 71, which is an intermediate portion of the catheter 11, and there is no significant difference in rigidity at the small cross-sectional area 71. It is difficult to concentrate the stress in the cross-sectional area 71, and it is possible to provide the catheter 11 that can suppress the occurrence of breakage and kink of the catheter 11.

In addition, the catheter 11 of this embodiment can be manufactured by the following method.
First, the inner layer 40 is formed by extrusion or the like. Then, after the linear body 51A is wound around the inner layer 40 to form the reinforcing body 50A, the outer periphery of the reinforcing body 50A is shaved by a router or the like, or the linear body 51A before being wound around the inner layer 40 is arbitrarily selected. Is polished in advance, and the polished linear body 51A is wound around the inner layer 40 to form the small cross-sectional area 71. Thereafter, the outer layer 60 is formed by extrusion or the like on the outer periphery of the inner layer 40 and the outer periphery of the reinforcing body 50A having the small cross-sectional area 71 and covering the outer periphery of the inner layer 40. The method of manufacturing the catheter 11 is not limited to this method. For example, the linear body 51A may be polished by electrolytic polishing or the like, and various known methods can be adopted.

[Example 2]
Second Embodiment A catheter 12 according to a second embodiment will be described with reference to FIG. Components having the same configuration as in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The reinforcing member 50B of the hollow shaft 22 of the catheter 12 includes a linear member 51B having a circular cross section wound around the outer periphery of the inner layer 40.

  Further, among the reinforcing members 50B, at a position separated from the distal end of the reinforcing member 50B toward the base end side, and at a position separated from the base end of the reinforcing member 50B toward the distal end side, A small cross-sectional area 72 is formed.

  As shown in FIG. 3, the linear body 51 </ b> B of the small cross-sectional area 72 formed in the middle of the reinforcing body 50 </ b> B (that is, the middle of the catheter 12) As compared with the linear body 51B, the cross-sectional area gradually decreases along the longitudinal direction of the reinforcing body 50B toward the center C of the small cross-sectional area portion 72. That is, in the small cross-sectional area 72, the linear body 51 </ b> B is tapered to decrease in diameter toward the center C of the small cross-sectional area 72.

  With such a configuration, a portion that can be more easily bent can be formed at the central portion of the small cross-sectional area portion 72, and the difference in rigidity becomes gentler, so that the stress at the small cross-sectional area portion 72 is reduced. Can be dispersed, so that breakage and kink of the catheter 12 can be further suppressed.

[Example 3]
Third Embodiment A catheter 13 according to a third embodiment will be described with reference to FIG. The components having the same configuration as those of the first and second embodiments are denoted by the same reference numerals, and the description will be omitted.

  In the hollow shaft 23 of the catheter 13, the outer layer 61 provided on the outer periphery of the reinforcing body 50B has a first resin layer 62 covering the small cross-sectional area 72, and a proximal end to a proximal end of the small cross-sectional area 72. A second resin layer 63 covering the portion of the reinforcing body 50B on the side, and a third resin layer 64 covering the portion of the reinforcing body 50B on the tip side from the tip of the small cross-sectional area 72. I have.

  The resin forming the first resin layer 62 is made of a material that is more flexible than the resin forming the second resin layer 63. The third resin layer 64 may be made of a material having the same flexibility as the first resin layer 62, or may be made of a material more flexible than the first resin layer 62. May be.

  In such a configuration, since the first resin layer 62 covering the small cross-sectional area 72 is more flexible than the second resin layer 63, the catheter 13 can be more easily bent at the small cross-sectional area 72. Can be.

  Here, the soft resin material refers to, for example, a soft resin material having a lower hardness when comparing, for example, Shore hardness indicating the hardness of the resin, but is not limited to this, and has a longitudinal elastic modulus. Also, a resin having a low flexural modulus is a flexible resin material. As a specific example, even with the same polyamide elastomer, a soft resin material can be formed by increasing the ratio of the soft segment to the hard segment. May be applied to the resin layer 62.

In addition, the catheter 13 of this embodiment can be manufactured by the following method.
First, an inner layer 40 and a reinforcing body 50B having a small cross-sectional area 72 for winding the outer periphery of the inner layer 40 are prepared. Also, the first resin layer 62, the second resin layer 63, and the third resin layer 64 are formed in advance by extrusion, and the first resin layer 62, the second resin layer 63, and the third resin layer 64 are formed on the outer periphery of the prepared inner layer 40 and the reinforcing member 50B. The resin layer 62, the second resin layer 63, and the third resin layer 64 are covered. Thereafter, a heat-shrinkable tube is covered so as to cover the outer periphery of each of the resin layers 62, 63, and 64, and the heat-shrinkable tubes are heated, so that each of the resin layers 62, 63, and 64 is prepared and the prepared inner layer 40 and reinforcing member The catheter 13 is manufactured by closely adhering to the outer periphery of 50B. Further, the present invention is not limited to this method, and various known methods can be employed.

[Example 4]
Fourth Embodiment A catheter 14 according to a fourth embodiment will be described with reference to FIG. The components having the same configurations as those of the first to third embodiments are denoted by the same reference numerals, and description thereof is omitted.

  In the hollow shaft 24 of the catheter 14, the outer layer 65 provided on the outer periphery of the reinforcing member 50B includes a first resin layer 62 covering the small cross-sectional area 72, and a proximal end to a proximal end of the small cross-sectional area 72. A second resin layer 63 covering the portion of the reinforcing body 50B on the side, and a third resin layer 66 covering the portion of the reinforcing body 50B on the tip side from the tip of the small cross-sectional area 72. I have.

  For the resin forming the first resin layer 62, a material that is more flexible than the resin forming the second resin layer 63 is used, and the resin forming the first resin layer 62 is more flexible than the resin forming the third resin layer 66. Flexible materials are used.

  In such a configuration, since the first resin layer 62 covering the small cross-sectional area 72 is more flexible than the second resin layer 63 and the third resin layer 66, the small cross-sectional area At 72, the catheter 14 can be more easily bent.

[Example 5]
Fifth Embodiment A catheter 15 according to a fifth embodiment will be described with reference to FIG. The components having the same configurations as those of the first to fourth embodiments are denoted by the same reference numerals, and description thereof will be omitted.

  In the hollow shaft 25 of the catheter 15, the small cross-sectional area portions 72 are arranged at two places in the longitudinal direction. That is, the catheter 15 includes a distal-side small cross-sectional area 72a disposed on the distal side and a rear-side small cross-sectional area 72b disposed on the rear side. The cross-sectional area of the front-side small cross-sectional area 72a is the same as the cross-sectional area of the rear-end small cross-sectional area 72b. Note that a common resin layer may be located between the front-side small cross-sectional area 72a and the rear-side small cross-sectional area 72b. The first resin layer 62 in the area 72a corresponds to the second resin layer 63, and the third resin layer 66 in the rear end side small cross-sectional area 72b corresponds to the third resin layer 66. Corresponding.

  In such a configuration, the catheter 15 can be more easily bent at the two locations where the small cross-sectional area portions 72 are arranged with the same ease of bending. In the present embodiment, two small cross-sectional area portions 72 are provided in the longitudinal direction of the catheter 15, but the present invention is not limited to this, and two or more small cross-sectional area portions may be provided. The cross-sectional area of the front-side small cross-sectional area 72a and the cross-sectional area of the rear-end small cross-sectional area 72b may be different from each other.

[Example 6]
Sixth Embodiment A catheter 16 according to a sixth embodiment will be described with reference to FIG. The components having the same configurations as those of the first to fifth embodiments are denoted by the same reference numerals, and description thereof will be omitted.

  In the outer layer 67 of the hollow shaft 26 of the catheter 16, the outer diameter of the first resin layer 68 corresponding to the small cross-sectional area 73 is reduced toward the center C.

  With such a configuration, a portion that can be more easily bent can be formed in the central portion of the small cross-sectional area 73, so that the catheter 16 can be more easily bent at the small cross-sectional area 73. be able to.

[Example 7]
A catheter 17 according to a seventh embodiment will be described with reference to FIG. The components having the same configurations as those of the first to sixth embodiments are denoted by the same reference numerals, and description thereof will be omitted.

  In the hollow shaft 27 of the catheter 17, the reinforcing body 50C covering the inner layer 40 is formed of a net-like body in which two metal strands of a first linear body 51C and a second linear body 51D are woven. .

  In the middle part of the reinforcing body 50C, a small cross-sectional area portion 74 in which the cross-sectional area of each of the first linear body 51C and the second linear body 51D is smaller than the cross-sectional areas of other parts. Are formed.

As described above, by forming the catheter 17 having the mesh-shaped reinforcing body 50C, the strength of the catheter 17 is improved, and the catheter 17 is easily curved at the small cross-sectional area 74 while having the advantage of being hardly crushed. Further, stress is not concentrated in the small cross-sectional area portion 74, and as a result, the occurrence of breakage or kink of the catheter 17 can be suppressed.
Example 8
The catheter 18 according to the eighth embodiment will be described with reference to FIG. The components having the same configurations as those of the first to seventh embodiments are denoted by the same reference numerals, and description thereof will be omitted.

  In the hollow shaft 28 of the catheter 18, the outer layer 61 provided on the outer periphery of the reinforcing body 50 </ b> C includes a first resin layer 62 covering the small cross-sectional area 74, and a proximal end to a proximal end of the small cross-sectional area 74. A second resin layer 63 covering the portion of the reinforcing body 50C on the side, and a third resin layer 64 covering the portion of the reinforcing body 50C on the tip side from the tip of the small cross-sectional area 74. I have.

  The resin forming the first resin layer 62 is made of a material that is more flexible than the resin forming the second resin layer 63.

  In such a configuration, even when the reinforcing body 50C made of a braid is provided, the first resin layer 62 covering the small cross-sectional area portion 74 is more flexible than the second resin layer 63, In the small cross-sectional area 74, the catheter 18 can be more easily bent.

  In the present embodiment, the third resin layer 64 may be made of a material having the same flexibility as the first resin layer 62, or may be more flexible than the first resin layer 62. It may be made of a suitable material. Of course, similarly to the fourth embodiment, the first resin layer 62 is formed of a material that is more flexible than the second resin layer 63, and is formed of a material that is more flexible than the third resin layer 66. You may.

  The present invention is not limited to Examples 1 to 8 described above, and design modifications can be made as appropriate without departing from the gist of the present invention.

  For example, the reinforcing member 50A or 50B does not need to be constituted by one linear body 51A, 51B, and may be constituted by two or more multi-strand coils. Further, the linear body may be a stranded wire formed by a plurality of strands.

  Further, the cross-sectional shape of the linear bodies 51A, 51B, 51C, 51D is not limited to a circular shape as shown in Examples 1 to 8, but may be a polygonal shape such as an elliptical shape or a flat plate shape. Of course.

  The configuration in which the outer diameter of the first resin layer 68 corresponding to the small cross-sectional area 73 is reduced toward the center C as shown in Example 6 is applied to other embodiments. Of course, it is good.

11, 12, 13, 14, 15, 16, 17, 18 Catheter 40 Inner layer 50A, 50B, 50C Reinforcing body 51A, 51B, 51C, 51D Linear body 60, 61, 65, 67 Outer layer 62, 68 First resin Layer 63 Second resin layers 64, 66 Third resin layers 71, 72, 73, 74 Small cross section

Claims (3)

An inner layer made of resin;
A reinforcing member provided on the outer periphery of the inner layer and formed of a linear body,
An outer layer made of resin, provided on the outer periphery of the reinforcing member,
The reinforcing member is a position of the reinforcing member that is separated from the distal end of the reinforcing member toward the base end, and is positioned at a position that is separated from the base end of the reinforcing member toward the distal end, It has a small cross-sectional area portion in which the cross-sectional area of the linear body decreases along the longitudinal direction of the reinforcing body ,
The cross-sectional area of the small cross-sectional area is gradually reduced gradually toward the center of the small cross-sectional area along the longitudinal direction of the reinforcing body toward the center of the small cross-sectional area , A catheter characterized by the above-mentioned. The catheter according to claim 1,
The outer layer includes a first resin layer that covers the small cross-sectional area, a second resin layer that covers the reinforcing body on the base end side from the base end of the small cross-sectional area, and a tip of the small cross-sectional area. And a third resin layer that covers the reinforcing body on the distal end side, wherein the resin forming the first resin layer is more flexible than the resin forming the second resin layer. . A catheter of claim 請 Motomeko 2,
A catheter , wherein the resin forming the first resin layer is more flexible than the resin forming the third resin layer .

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